Volvo uses magnets in the road to help steer autonomous cars

Like many automakers, Volvo sees autonomous cars as the most significant means of minimizing road accidents as it would eliminate the number one cause of most crashes, human error. However, getting the infrastructure necessary for self-driving cars up and running, not to mention any legal requirements, remains a monumental task.

One of the biggest hurdles at present is reliable and highly accurate positioning. Most autonomous car prototypes rely on GPS and cameras for positioning, but there are major shortcomings to these such as poor weather or physical objects blocking the view of the cameras. A solution Volvo has come up with to get around this is to use a series of magnets buried in the road surface to help an autonomous car determine its position.

Volvo researchers created a 100-meter long test track at the company’s testing facilities in Hällered outside Gothenburg, Sweden. A pattern of round ferrite magnets was located about eight inches below the road surface. An autonomous car equipped with several magnetic field sensors was then driven along the road, using the magnets to help guide its way.

This initial round of testing was designed to evaluate crucial issues, such as detection range, reliability, durability, cost and the impact on road maintenance. The researchers found that ferrite magnets were an efficient, reliable and relatively cheap solution, both when it comes to the infrastructure and on-board sensor technology.

Volvo imagines the magnets being installed in existing road markings such as reflectors. And there are other benefits too. If cars with existing lane keep assist capabilities were fitted with magnetic field sensors, the magnets could be used to help prevent accidents where a car runs off the edge of the road or crosses the center line.

“The magnets create an invisible railway that literally paves the way for a positioning inaccuracy of less than one decimeter,” Volvo preventive safety leader Jonas Ekmark said in a statement. “We have tested the technology at a variety of speeds and the results so far are promising.”

The next step will be to conduct tests in real-life traffic, the automaker says.